The present disclosure relates to image forming apparatuses.
In general, digital color multifunction peripherals reproduce a full color image by adjusting tones of four coloring materials (e.g., toner) in colors of cyan, magenta, yellow, and black. Combination of the four coloring materials determines a color gamut (reproducible color range) that the multifunction peripheral can reproduce. The range of the color gamut varies depending on the amount of the coloring materials placed on a recording medium (e.g., paper). The range of the color gamut also varies depending on the state of the coloring materials melted on paper at fusing. For example, the coloring materials in an insufficient melting state reduce the color gamut. While on the other hand, the coloring materials in a uniformly melted state can expand the color gamut.
Where a color according to input data falls inside the color gamut that a multifunction peripheral can output (i.e., print), the multifunction peripheral can reliably reproduce the color. However, in general, the color gamut in which colors can be reproduced as output is narrower than a color gamut in input color space (e.g., sRGB, adobe RGB, etc.). For this reason, where a color in input data falls outside of the color gamut for output, the color is compressed up to a color inside the color gamut for output. As a result, the tone is lost at a part of an input image which has high color intensity to lead to unreliable reproduction of colors in the image. Further, in order to reduce the amount of toner consumption, devices have been generally designed so as to reduce the amount of toner in transfer to paper. Accordingly, the tone at the part having high color intensity is liable to be lost for the above reasons.
Some image processing device selects a color conversion profile with an optimum color intensity compression rate for a color gamut of input data to prevent degradation at the part having high color intensity.
Furthermore, another image forming apparatus performs transfer and fusing of an image to a recording medium by a desired number of times to expand the color gamut.